Safety mixer



yJunge 2, 1936 y F. L. cRADDocK 2,042,511

l SAFETY MIXER Filed oct. 1'7, 1931 27 %1 55 i 106 59 W//f//f 52 ma): z 11 '9 5 Hallum." 1f

Patented June 1936 UN1T1-:D STATES SAFETY MIXER Frederick L. Craddock, Rochester, N. Y., assignor to Mixing Equipment Company, Inc., Rochester, N. Y., a corporation of New York Application october 1v, 1931, serial No. 569,367

- Z Claims.

This invention pertains to the same type of apparatus as is described in my United States Patent No. 1,817,353 dated August 4, 1931, for Safety mixer.

5 A broad object of the present invention is to discharge the cooling air in an improved manner, for instance, so as to avoid creating drafts in the air surrounding the mix. Such drafts are found to be troublesome where the mix is of a photographic emulsion or of other very delicate materials.

Other objects are to provide suitable air guiding surfaces and associated devicesl to direct the air discharge as desired. 1 Y

Other objects may appear from the following detail description and may be pointed out in the appended claims.

Referring to the accompanying drawing:-

Flg. 1 is a side elevation of my improved mixer;

Fig. 2 is a cross section taken on the line 2-2 of Fig. 1;

Fig. 3 is a modification in which the air guide anges are designed to discharge the cooling air in umbrella-like formation; and

Fig. 4 shows said air guide flanges reversed to discharge the cooling air in inverted, umbrellalike formation.

The numeral I indicates the right-hand side of any tank in which the mix is to be made and upon which is fastened the clamp 3, made of cast aluminum, and detachably held in place by means of the hand-screw 5 which is provided with the hand-wheel 1.

The upper portion of the clamp 3 is provided with a hemispherical recess 9 in which is placed a hemispherical mating casting II, provided with a slot I3, in which is placed a washer I5, having two downwardly extending lugs I1 to prevent ro- 0 tation of the washer I5 with respect to the casting II.

A bolt, I 9, having its head at the lower end, in a recess in clamp 3, extends upwardly through washer I5, and is secured by a nut 23.

Thus the clamp 3 and the casting II may be adjustably locked in position with respect to each other by the nut 23. 'I'his adjustability is equivalent to that of a ball and socket joint and is universal for any practical position of the mixing propeller 25 in the tank I.

The casting II extends as indicated and surrounds the lower portion of a motor 21, to which it is attached by screws 29, which enter the tapped holes 3|, such as are found in standard motors of this type.

The casting |I also extends downwardly to forni an outboard bearing which contains a stuii'-y ing box and bushing 32 for the hollow portion 33 of the propeller shaft 33-35. Members 33 and 35 are held together by a chuck |00, and wrench jaw grip flats 34 are formed on shaft 33. The 5 eld yoke (or, in the case of an alternating current motor, the stator) I0| is provided with conventional end closure members |02 and I 04, and a member of radial cooling anges |03 which are surrounded by acylindrical casing |05, thus form- 10 ing an air confining passage wherein heat generated in the motor may be transferred to air flowing through the passages I 03. 'I'he heat laden air is discharged radially through the slots |06, best shown in Fig. 2, and the direction of the 15 discharge is further guided by the air guide flanges |060 which are secured by screws I06I to casting II. l

At an upper extension |01 of the motor shaft 39 there is mounted a centrifugal blower fan |09 20 surrounded by a casing III, formed by an extension of casing I 05, and having a hole II3 at its central portion. The fan thus draws in free air positioned far enough away from the mixing member to be free of spray or vapor. 25

When a motor of this improved type is operated in conventional applications other than in my improved mixer it has the advantage of being dustproof, flreproofv and self-cooling, but when operated in combination with the other 30 parts of my mixer an additional advantage develops of blowing' any emanations of the mix away from the motor 21 in such a manner as to disturb the air at the surface of the mix as little as possible as well as avoiding the agitating of 35 dust and disturbing the surrounding air.

A construction such as that shown in the drawing where both the cooling air in the motor and the propeller stream of the mixture in the tank are caused to discharge in directions substantially perpendicular to each other appears to have advantages of efficiency and convenience as compared to other possible arrangements.`

By drawing air in axially at one end of the mo- 5A tor and discharging it radially at the other, a' 4 very minimum of air disturbance occurs at the surface of the mix while perfect cooling is retained.

The modifications of Figs. 3 and 4 show a pair of air guide flanges |30 which are curved so as 50 to guide the heat laden air in umbrella formation when mounted as shown in Fig. 3 or` in inverted umbrella formation when mounted as shown in Fig. 4 Flanges |30, by defiecting the heat laden discharge air either upwardly or 55 downwardly, are designed. to aid in controlling the air disturbance where suchcontrol is desirable under particular mixing conditions.

As an additional precaution for use in special- 1y inflammable mixes, I provide a coupling flange H5 on casing Ill which carries one end of an intake hose H9 the remote end of 4which draws in fresh air from the outside of the building at the port-hole lli.

The direction of the air circulation through the various above described parts of the apparatus is indicated in the drawing by arrows.

I claim:-

1. An improved safety mixer provided with a shaft. an airjacketed motor in driving relation to the shaft, having a fan at one end, an air discharge lport at the other end. a cored end bracket designed to defiect the air from the JacketV :toward the shaft and then away from the shaft whereby the whole adjacent motor end maybe cooled, said end bracket being provided to the shaft. having a fan at one end, an air 'may be cooled, said end bracket being provided with narrow radial members designed for minimum interference with airflow and connecting 

